A conventional disc brake is equipped with a parking brake mechanism configured to thrust a piston and keep the piston at a braking position at the timing of activating a parking brake or the like. The parking brake mechanism includes a ball and ramp mechanism and a screw mechanism. The disc brake employs a configuration to operate the ball and ramp mechanism and the screw mechanism by rotation of an electric motor, so as to move the piston to the braking position and keep the piston at the braking position by the screw mechanism (refer to Patent Literature 1).